Mod: MDM/011/M4 Rev 2
IDS GeoRadar
User Guide
QGG/2021/001
Rev. 1.4
o
Although the radar can measure differential displacements (between two successive
acquisitions) with sub-millimeter precision it must be reminded that errors in the
displacement measurement cumulate with the observation time and its effective value
is dependent on many factors, such as reflectivity of the monitored surface,
atmospheric variations etc.
o
The technology used measures the displacement along the line of sight only. The
number of radars to be installed and their locations must be then carefully chosen to
reduce the presence of uncovered or not properly covered areas (e.g. movement
vectors occurring perpendicularly or close to a perpendicular to the line of sight).
o
Monitoring Products measure the relative line of sight displacement between the radar
and the monitored surface. In case the radar is installed on an unstable location, the
movement of the radar setup could be interpreted as deformation of the monitored
surface.
o
The accuracy of the Monitoring Products in deformation measurement is dependent on
the strength of the signal reflected back by the variable ground surface; performance
cannot be uniform on the entire monitored scenario; e.g. some areas may not produce
a signal strong enough to enable a proper early detection of collapses. Particularly, the
radar signal can be affected by the presence of vegetation on the slope.
o
Movement of portions of terrain which are (or are close to) perpendicularly oriented
with respect to the radar line of sight, could be underestimated or, even, undetected.